The utilization of high permeability material such as powdered molybdenum iron-nickel alloy in the cores of loading coils has been long known in the communications industry. Such materials are conventionally compressed at extremely high pressures such as 100 to 150 tons per square inch, subsequently annealed to improve magnetic and structural properties, and, finally, insulated as by a baked varnish coating. One piece cores have been made in full toroids, however, that shape presents several disadvantages in the industry. By virtue of its single surface closed construction, the toroidal core requires any- coil being placed around the core to be wound directly about the shape. Thus, any insulation required between the winding and the core material must be either placed on the winding or coated directly on the toroid which further necessitates special handling of the winding and the core insulation. Additionally, there are limitations to the winding of a coil around the toroidal core in that automatic winding on such a shape is difficult, and in the cases of a heavy conductor, is impossible thereby necessitating hand winding. In order to circumvent these manufacturing problems, cores have been made in L shapes with two of these shapes subsequently assembled to form toroid cores. It has been necessary in the past in making sectional cores to employ a molding die made up of a plurality of removable die sections in order to permit withdrawal of the formed L from the die cavity. The die sections forming the L-shaped cavity conventionally are individually clamped on a suitable platform in an abutting sort of relationship and after the required pressure has been applied to a charge of powdered material within the cavity the die sections are unclamped from the platform and moved away from the formed body to permit removal of the compressed core. Both the core section shape and the method of making that shape present serious disadvantages which are overcome by the shape and method of manufacture of this invention. For example, the necessity of repetitive clamping and unclamping of the plurality of die sections in the forming operation for L shapes results in rapid deterioration of the die sections which results in varying core shapes. Further, the occurrence of gaps between the die sections upon reassembly for another molding contributes to further non-uniformity of the shape of the product formed therein. The inherent mobility of assembled die sections contributes to non-rigidity of the die cavity allows non-uniform compression of the charge of powdered material within the cavity under the high compressing pressures. Non-uniform compression results in a non-uniform density of material, an irregular shape, as well as internal stresses within the material, all of which contribute to the disadvantages of the process. Additionally, the necessity of unclamping assembling and disassembling and clamping the die sections to remove the formed core and to prepare for another operation does not lend to any sort of automated manufacturing operation.